Maize
(2n = 40) x Tripsacum dactyloides (2n = 72) F1 hybrid plants
(2n = 56) were obtained by embryo rescue and induction of somatic
embryogenesis/organogenesis. Hybrid plants showed Tripsacum-like
phenotypes, tolerance to stresses such as NaCl salinity and low temperatures.
The more frequent meiotic configurations were 28II (24%), 24II + 2IV
(19%) and 26II + 1IV (12%), with an average per cell of 0.55I + 25.18II
+ 1.19IV. Significant differences between plants were not observed.
Pollen fertility ranged from 0% to 50%. After pollination with maize
or Tripsacum, 20% of F1 plants have developed viable seeds,
which originated the progeny. Thirty five percent of the progeny showed
2n = 56 chromosomes and F1 like-phenotypes, which suggests they have
apomictic origin. The remaining plants were fertile and they showed
maize-like phenotypes and different chromosome numbers (2n = 22, 24,
26, 28 and 30), because they kept the complete maize chromosome complement
and some of the Tripsacum chromosomes. Meiotic cells showed
pairing between chromosomes from both parental species, which suggests
the possibility of genetic recombination between them.